지도서 · Part 4–6 · 4 / 4

Estimate on a number line수직선에서 어림하기

Find halfway. Which end is closer? A good estimate is close.

Step 11워크북 5–7쪽 →
한국어 요약

눈금에 숫자가 없을 때 화살표가 가리키는 수를 어림하고, 수가 놓일 자리를 표시하는 법을 영어로 가르쳐요. 가운데 찾기, 더 가까운 끝 고르기, 머릿속으로 10칸 나누기, 기준점에서 확인하기의 네 단계를 대본과 놀이로 담았어요.

이 주제의 단어estimateabouthalfwaycloser tointerval
이 주제 차례 (9)

The big idea핵심

To estimate is to find a number that is close. A good estimate is close. It does not have to be exact.

Use four steps. 1. Find halfway. 2. Is it closer to the start, to halfway or to the end? 3. Split the line into 10 parts in your head. 4. Check from the nearest number you know.

It works both ways. Read an arrow and say the number. Or take a number and draw an arrow where it goes.

050100A
A is more than halfway. It is about 70.
010010
10 is much less than halfway. It goes close to 0.

Get ready준비물

  • The floor line or paper line from Part 1, with only 0 and 100 written on it
  • A small toy to use as a marker
  • The 10s cards from Part 1, to check

Teach it, step by step단계별 수업

YOU 부모가 할 말LIA 아이가 할 만한 대답DO 손으로 할 일

Find halfway

DOShow a line with only 0 and 100 on it.
YOU“Where is halfway? Put your finger on it.”
LIAHere, in the middle.
YOU“What number is halfway between 0 and 100?”
LIA50.

Which end is closer?

DODraw an arrow a little past 70.
YOU“Is the arrow closer to 0 or to 100?”
LIATo 100. It is more than halfway.
YOU“So is the number more than 50 or less than 50?”
LIAMore. Maybe 60 or 70.

Split it in your head

YOU“Imagine 10 jumps of 10 from 0 to 100. Where would 60 and 70 be?”
DOLet Lia point to where 60 and 70 would be.
LIAThe arrow is near 70. It is about 70.
YOU“Great estimate. A good estimate is close. It does not have to be exact.”

Accept any answer that is close, like 67 or 73. Praise the steps she used, not only the number.

Now mark a number

YOU“Where does 10 go? Is 10 more or less than halfway?”
LIALess. Much less.
YOU“So is it close to 0, or close to 50?”
LIAClose to 0. Here.
DOLet Lia put the toy there. Then check with the 10s cards from Part 1.

Many young children put 10 near the middle of a 0–100 line. Asking about halfway is the quickest fix.

Check from a number you know

YOU“Mark 46.”
LIAIt is a bit less than halfway. Just before 50.
YOU“Check from 50. How far is 46 from 50?”
LIAOnly 4. So it is very close to halfway.
광고

Other ways to say it다른 표현

  • “Is it closer to 0 or to 100?”
  • “Where is halfway?”
  • “Is it more or less than halfway?”
  • “It is about 70.”
  • “It is a bit more than halfway.”
  • “It is a bit less than halfway.”
  • “Roughly where does 30 go?”

Worksheet English표현

  • “Estimate the number the arrow is pointing to.”
  • “Draw an arrow to show where 28 goes.”
  • “Mark 85 on the number line.”
  • “Explain how you know.”

Good questions to ask좋은 질문

  • “Explain how you know.”

    Good answers

    “It is a bit more than halfway, so it is more than 50. It is near 60.”

  • “Is your estimate sensible?”

    Note

    If the arrow is near 100, an answer like 20 is not sensible.

  • “Is 10 more or less than halfway?”

    Good answers

    “Less. 10 is much less than 50, so it goes close to 0.”

  • “Can a different number also be a good estimate?”

    Note

    Yes. 67, 70 and 73 can all be good estimates for the same arrow.

If Lia is stuck막힐 때

  • When

    On a 0 to 100 line, Lia puts 10 near the middle.

    “Where is halfway? Is 10 more or less than halfway?” Then: “Is 10 close to 0, or close to 50?”

  • When

    She is upset because her estimate is not exactly right.

    “An estimate only needs to be close. 67 is a great estimate for 70.” Praise the steps she used.

  • When

    She counts tiny steps from 0 to find the arrow.

    Find halfway first. Then start from the nearest number you know: 0, 50 or 100.

  • When

    On a 0 to 20 line, she says halfway is 50.

    “What are the numbers at the ends? Halfway between 0 and 20 is 10.” Read the ends before you start.

Game놀이

Game · Stand on the number

You need: the floor line with only 0 and 100 on it, the 10s cards from Part 1

  1. Call a number: “Stand on 30!” Lia walks along the line and stops where she thinks 30 is.
  2. She says why: “30 is less than halfway, so I am closer to 0.”
  3. Check with the 10s cards. Close counts as a win! Then swap: you stand somewhere, and Lia estimates your number.

Extra challenge더 도전

  • On a line from 0 to 50, where is halfway? Mark 30.
  • On a line from 20 to 40, which number is halfway?
In the workbook

Estimate arrows on lines from 0 to 100, 0 to 20 and 0 to 50, mark numbers with arrows, and decide if two friends are right.

워크북 5–7쪽 보기이 주제 인쇄

자주 묻는 질문

어림은 영어로 어떻게 말해요?

estimate라고 해요. “It is about 70.”처럼 about을 붙여 답하고, “It is a bit more than halfway.”처럼 까닭을 함께 말해요.

어림한 답이 정확하지 않아도 되나요?

네. 어림은 가까우면 돼요. 70을 가리키는 화살표에 67이나 73이라고 해도 좋은 어림이에요.

광고